Boy, this BBS sure eats a lot of my posts. The first copy of this post was about the third or fourth of my posts it has eaten.

I have posted to this BBS more frequently than any other user, and the BBS has never eaten any of my posts. Well except on the occasions when it's crashed, and it hasn't crashed today.

So I would guess it's something in what you're doing, or something wrong with your browser or your internet connection. Are you simply hitting the "back" button on the "preview post" screen, perhaps? Remember the BBS (by default) lets you preview and edit a post before confirming it.